Web-based customer reviews are frequently used by individuals in researching potential purchases. Customers who leave reviews are often themselves in the position of researching a variety of alternatives before deciding upon their eventual purchase. Potential customers, also referred to as users, may consider a number of alternative purchases and gather a variety of information to assist with their comparison and eventual decision. A user may consider a combination of factors, such as price, availability, features, and reviews (including their content and reliability), in making her purchase decision. Users' methods for keeping track of such comparisons can vary. Some users may mentally store and compare information about the alternatives under consideration. Others may use crude notes on paper, in a word processor or in a spreadsheet.